<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>border</title>
    <style>
        .c1{
            height: 300px;
            width: 500px;
            border: 3px dotted greenyellow;
            border-left: 3px solid gold;
            margin: 100px;
        }
        .c2{
            height: 50px;
            width: 200px;
            background-color: #555555;
            border-left: 4px solid transparent;
            color: #D3E7E9;
            margin: 100px;
        }
        .c2:hover{
            border-left: 4px solid #ff9e80;
        }

    </style>
</head>
<body>
    <div class="c1">这是一个边框示例</div>
    <div class="c2">边框透明色预设置占位，悬停时取消晃动</div>

</body>
</html>